code: def observe(self, reward=0, terminal=False, **kwargs):
      if self.callbacks.get("before_observe") is not None:
          self.callbacks["before_observe"]()
  
      self.current_state = None
  
      self.current_reward = reward
      self.cumulative_reward += reward
  
      self.analytics_client.track(
          event_key="REWARD",
          data={
              "reward": self.current_reward,
              "total_reward": self.cumulative_reward,
          },
      )
  
      if terminal:
          self.analytics_client.track(
              event_key="TOTAL_REWARD",
              data={"reward": self.cumulative_reward},
          )
          self.logger.log_metric(
              "episode_reward", self.cumulative_reward
          )
  
      if self.callbacks.get("after_observe") is not None:
          self.callbacks["after_observe"]()
  
file_path: SerpentAI/serpent/machine_learning/reinforcement_learning/agent.py
imports: from serpent.config import config
  from serpent.analytics_client import AnalyticsClient
  from serpent.logger import Loggers
  from serpent.loggers import *
  from serpent.enums import InputControlTypes
  from serpent.utilities import SerpentError
  import os
  import json
  import time
  import random
  import numpy
label_desc: Use image node_id 3 for calling the Agent obj's underlying member method code with example usage: obj.observe(reward, terminal) without return types